The present invention relates to a prosthetic device and more particularly to a prosthetic knee.
The human knee is a complex arrangement of ligaments, cartilages, and bone surfaces. The human knee is a versatile component that when properly operating can withstand various loads and forces being applied to it. When such various forces are applied, the knee adapts and moves in relation to those forces.
However, because the knee is subjected to great loads and tremendous use, the knee is subject to a host of different ailments, all of which result in discomfort and pain. Osteoarthritis, for example, commonly occurs in older people, and is typically found in the weight bearing joints of a human body, such as the knee and the hip. When osteoarthritis effects a knee, the articular cartilage of the knee degenerates, and the femur and tibia typically begin to wear against one another. This results in pain and stiffness in the joint, and makes flexion and extension of the knee difficult. People suffering this condition are often unable to partake in even the simplest physical activities.
Also, injuries to the articular cartilages of the knee often may arise from any of a plurality of sporting activities, like jogging and skiing, that exert substantial forces on the knee. Additionally, accidents and falls apply substantial forces to a knee. Such substantial forces may result in the damage or destruction of the articular cartilages in the knee.
Several prosthetic devices are presently available to assist individuals with knee ailments. These devices, however, have shortcomings, such as when loads and forces are applied to the components of the prosthetic some of the components slip away from each other. When such slippage occurs, the conventional prosthetic knee has difficulty joining the components together. For example, in one embodiment of a prosthetic knee the components lock together by a tongue and grove system. In another embodiment of a prosthetic knee, the components contact each other on curved and/or flat surfaces. When these components disengage from each other, they are difficult to mate together. The present invention allows some slippage and simultaneously corrects the slippage.
The present invention relates to a prosthetic knee. In one embodiment of the present invention, the knee has a femoral body and a meniscal body. The femoral body has a femoral alignment member, and the meniscal body has a femoral side. Extending from the femoral side are at least two guiding protrusions that extend along the longitudinal axis of the meniscal body and define at least two sides of an alignment groove. The alignment groove slippingly receives the femoral alignment member. The femoral alignment is able to move within the alignment groove and slip over the alignment groove when a force of sufficient magnitude is applied to the prosthetic and revert into the alignment groove. In another embodiment of the present invention, the groove and the alignment components are reversed on the respective femoral and meniscal bodies.